1. Field of the Invention
The present invention relates to a dental hygienic device having a structure based on and utilizing a photoelectric chemical reaction, and more particularly to a dental hygienic device adapted to improve sanitary conditions of teeth by means of an electrical polarization and chemical reduction which are produced by electrical energy that is converted from photoenergy by a semiconductor under coexistence of a light beam, water and the user's teeth.
2. Description of the Prior Art
Tooth powders or pastes contain an adequate amount of fluorine compounds because such flourine compounds have proved to be effective for promoting healthy teeth.
Teeth surfaces however tend to prevent anions, such as fluorine, from permeating the teeth since the teeth are covered with saliva which have a pH value lower than the pH value of the teeth. It has been, therefore, very difficult to obtain satisfactory effects from e.g. fluorine.
In some proposals for solving such a problem, a cathode is attached to a brushing head of a toothbrush. In use of such a device, the teeth-ridges or teeth per se will act as a cathode while the human body will function as a conductor whereby under presence of saliva and/or drinking water an electrolytic reaction takes place as follows: EQU H.sub.2 O.fwdarw.1/20.sub.2 +2H.sup.+ +2e.sup.- . . . (anode reaction), EQU 2H.sup.+ +2e.sup.- .fwdarw.H.sub.2 . . . (cathode reaction)
and as the result, EQU H.sub.2 O.fwdarw.1/20.sub.2 +H.sub.2.
The above reaction improves the permeability of fluorine ions.
This technique is however not convenient in that is needs a comparatively large consumption of electric power for such reactions since the human body (the electric resistance of which is high) is used as a circuit component. Its further disadvantage resides in the fact that there is a considerable difference between individuals in view of electric resistance to such a degree that the required current strength for such reactions might not be achieved. Moreover, misapplication of a high voltage which would overcome the problem could cause injury to the user's body. Hence, a novel technology has been sought which would not have the above-discussed disadvantages of electrolysis notwithstanding the utilization of electric energy.